Global sea-level rise is one of the most discussed potential consequences of global warming. The most uncertain aspect of such future sea-level change has to do with the marine based ice sheets, and particularly that of the West Antarctic Ice Sheet (WAIS). Despite its potential importance, current generation global climate models are unable to simulate sea-level change arising from ice sheet-ocean interaction.

As a step towards remediating this situation, we are bringing together, through annual workshops, the international modeling community with expertise in this area so to advance the state-of-the-art in regional-scale simulations. The outcome of these workshops will be physically-based estimates of sea-level change coming from WAIS over the present century and beyond. Such regional-modeling research will lay the groundwork for including ice sheet-ocean interaction in global scale, IPCC class models.

MISOMIP Experiments

Our first annual workshop, “Rising Coastal Seas On A Warming Earth,” was held from 27-29 October 2014 at the New York University Campus in Abu Dhabi, United Arab Emirates. The workshop included more than 30 leading researchers from around the world working toward coupled ice sheet-ocean modeling. The workshop included a series of brainstorming sessions, culminating in a plan for a series of community activities, progressing from separate ice sheet and ocean components toward coupled models and from idealized to realistic model setups. Participants felt that the idealized experiments should leverage an existing community effort focused on standalone ice sheet models, the third Marine Ice Sheet Model Intercomparison Project (MISMIP+), built on the earlier MISMIP and MISMIP3d projects. We envisioned a companion exercise focused on standalone ocean models, the second Ice Shelf Ocean Model Intercomparison Project (ISOMIP+), which would also build on the earlier ISOMIP project and the coupled modeling of Goldberg et al. (2012a,2012b). A third community experiment, the first Marine Ice Sheet-Ocean Model Intercomparison Project (MISOMIP1), would essentially couple together MISMIP+ and ISOMIP+. Design of these three interrelated MIPs has since proceeded with input from both workshop participants and the broader ice sheet-ocean modeling community. A design document covering all three projects is currently under review in Geoscientific Model Development.

A follow-up workshop, including discussion of the first modeling results took place on May 15-18, 2016 at NYU Abu Dhabi.

Diversity of Models

The types of models we are bringing together vary in complexity, ranging from one-dimensional flowline ice sheet models and simplified plume ocean models to fully three-dimensional, state-of-the-art models. As few ice sheet and ocean models have been coupled, either synchronously or asynchronously, the series of MISOMIP experiments have been designed to assist participants in validating first individual, standalone components and then the fully coupled system. While the near-term effort is focused on model validation in an idealized setting, our longer-term focus of the community modeling effort overseen by MISOMIP will be to help to answer our key target question: What is the response of WAIS to IPCC scenario climate forcing?

Community Building

We propose to bring together the richly diverse, developing, and at present largely uncoordinated international ice sheet-ocean modeling efforts to design and carry out an ensemble of simulations that project the future of WAIS. Bringing this community together for focused workshops will strengthen collaborations, improve models, and ultimately lend greater credibility to simulations of WAIS’s contribution to global sea-level change.